Snowboarding has become a major sport and is enjoyed by millions of snowboard riders in the U.S.A. and in many other countries the world over. A complete snowboard setup comprises the board itself and a pair of bindings that couple the rider's boots to the board. Threaded inserts are fixed in an upper surface of the board, and each binding is connected to the board by machine screws that pass through a base plate of the binding into the threaded inserts. Typically the threads are 6 millimeters (mm) in diameter and the screws are Phillips oval-head 6 mm screws long enough to extend through the base plate into the inserts; a length of 12 mm is common although some bindings may require longer or shorter screws.
Most snowboards have more inserts than are needed to secure the bindings to the board. This is so that the bindings can be placed in any of a plurality of locations according to the preference of the rider. Typically some inserts are arranged in two parallel rows near the nose of the board, oriented along the board's longitudinal axis, and other inserts are similarly arranged near the tail. The rows are spaced 40 mm from each other and the inserts in each row are spaced either 20 mm or 40 mm apart. A typical board has two such rows of inserts, with six to eight inserts in each row, near the nose, for mounting the leading-foot binding. Similarly, two rows of inserts are located near the tail for mounting the trailing-foot binding.
The base plate may have four screw holes spaced 40 mm apart to define a 40×40 mm square with one hole at each corner. Some base plates have more than four holes, and some have slots that can accommodate a screw at any position along the slot, to give a greater range of possible mounting positions. Regardless of the number of holes in the base plate or whether the holes are round or slot-shaped, four screws are used to mount the base plate to the board using four of the inserts.
The base plate typically has a beveled edge that mates with a correspondingly-beveled edge in an opening in a mounting plate of the binding. When the base plate is screwed tightly on to the board, these edges engage and the mounting plate is clamped to the board. These beveled edges commonly have mating serrations similar to the teeth of a gear, and when the base plate is tightened onto the board these serrations mesh, locking the mounting plate securely to the base plate and through it to the board.
The angular orientation of the base plate relative to a lateral axis of the board is fixed by the inserts and the mounting holes. But the mounting plate can be rotated about its vertical axis into any of a plurality of angular orientations relative to the lateral axis. For example, the serrations may be configured such that any angular multiple of 3° may be selected. This permits the binding to be rotated to an angle of ±3°, 6°, 9°, etc., relative to the lateral axis, where a positive angle indicates that the binding is rotated so that the toe points toward the nose of the board.
Although most bindings are secured using four screws, some boards use a three-screw mounting system in which the inserts are irregularly spaced along the longitudinal axis of the board and the base plate has holes arranged in a generally-triangular pattern to allow for positioning the mounting plate in any desired angular rotation and in any of a plurality of longitudinal positions as desired by the rider.
Some riders choose positive angles for both feet with the trailing foot at a smaller angle. This kind of orientation is often preferred for alpine racing and for some big-mountain riding. Angles may be set to +20° or more for the leading foot and +12° or more for the trailing foot. Other riders prefer a “duck foot” stance in which the leading toe points toward the nose of the board and the trailing toe points toward the tail; this is often preferred by freestyle riders, especially for doing tricks in terrain parks and half pipes. A duck-foot rider may choose angles such as +12° and −6° for leading and trailing bindings, respectively. Others may select wider angles and a symmetrical stance such as ±15°.
It is important that the screws remain tight despite shocks and vibration that occur when snowboarding so that the rider's boots remain coupled to the board in the desired orientation. Lock washers are sometimes disposed on the screw between the screw head and the base plate. A chemical thread holder such as “Loctite” made by Henkel AG of Düsseldorf, Germany, is sometimes applied to the threads to prevent the screw from loosening. In addition, many ski resorts provide workbenches and screwdrivers so that riders can tighten the screws as needed during a day of riding.
If a rider wishes to change the stance angle, the screws holding the base plate must be loosened enough to permit the mounting plate to rotate under the base plate, and then the mounting plate is rotated to the desired stance angle and the screws are re-tightened. This may happen frequently, either as a rider moves from one style of riding to another, or if a rider wants to experiment with various stance angles.
If a rider wishes to change the stance width, by moving the bindings closer together or further apart, or if the rider wishes to reconfigure between regular and goofy stance, the screws holding the base plate must be removed so that the base plate can be relocated as desired.